Sealing composition



Patented Nov. 3, 1936 SEALING COIVHOSITION Fred Stevens, Birmingham,Ala., assignor' to American Cast Iron Pipe Company, Birmingham, Ala., acorporation of Georgia No Drawing. Application June 1, 1935, Serial No.24,583

6 Claims.

ing used to effectively seal a threaded or other joint in cast iron,steel or other metals. The essential function of every threadingcompound is to reduce friction and obtain a metal to metal contact inthe joint. It has been demonstrated that my present new and improvedcompound enables this to be accomplished much better than 'is possiblewith other compositions heretofore known and used for the same purpose.The na- .ture, function, utility, alternative modifications,

practical application, methods of preparation, and special qualities ofthe compound, as well as "various satisfactory formulae for compoundingthe ingredients of this material, will be readily understood from thefollowing description, which is sufliciently exact to enable a skillfuluser to practice the same; at the end of which description the inventionis carefully summed up and covered in several clauses of claim, and thebreadth of the invention is not to be limited in any way except by theclaims.

My improved composition consists of three ingredients, namely,paraiflne, White lead and linseed oil. These are mingled or combinedtogether in specified proportions and by suitable methods of admixtureas well as in different forms or conditions, but the paraffine is thebasic element of the compound, and in order to gain the best results theparaffine is generally used in a volume in excess of that of the othertwo elements, and sometimes it is very greatly in excess; but in everyvariation in the proportions of the ingredients by volume the paraiflneis in suspension in the mixture in the form of flakes, particles orglobules for it combines readily with the oil and is distributed rapidlythroughout the mixture. Wherefore the composition is always normallyplastic or soft, and never brittle or hard, or of great density. Thisresult is insured in the .largest degree when the paraffinepredominates,

but much latitude may be allowed in the proportioning of the paraflineto the white lead and the linseed oil without sacrificing the value ofthe invention. The white lead gives pliability and flexibility and theparaffine unites intimately with the linseed oil so that the mass iskept plastic or fluent, and is easily applied, and is never indurated. Ido not confine myself to the use of all the specific ingredients, butcontemplate the use of their equivalents without restricting myself tounessential details. Possibly the white lead may be omitted or at leastsubstituted with a natural filler.

I will proceed now to describe certain leading ways or examples amongmany that may be set forth in which my improved thread compound may beprepared and used, from which it will be seen that while the white leadand the linseed oil are important, yet they may at times be substitutedwith equivalent substances having similar 10 properties, while theprafline usually in a disproportionate volume is of paramount value.

In one example of making up the sealing material, equal parts ofcommercial white lead, linseed oil and parafiine are used. This mixtureis heated slightly above the melting point of parafflne, and then verythoroughly commingled. While the mixture is hot it is a relatively thinliquid and can then be applied tothe threads of a pipe, or to any otherpart, with a brush after which it almost immediately solidifies. Thecompound so formed produces satisfactory results, but somewhat less ineffectiveness than when the parafline is in excess of the otherelements. Obviously, the application on the threads of a pipe takesplace before screwing the pipes together to make a pipe joint.

In a second suggestive example confirmed by experience, one part ofwhite lead is used to one part of linseed oil, and twenty-five parts ofmelted parafline. This mixture may be beaten up with an ordinary powerbeater and when it cools it will be in the form of a fluffy paste. It isapplied in the paste form after it has cooled, to the pipe threads orother metallic surfaces.

A third example or way in which the material isdeveloped for use is totake one part of white lead, one part of linseed oil, two parts ofpowdered parafiine or other wax, all by volume, and mix them togetherwith an ordinary power beater and without theapplication of any heat.The powdered paraffine is obtained in any simple or convenient Way, as,for example, by taking the ordinary cake parafline and grating itthrough a twenty-one more or less mesh screen to reduce it to aflakelike form. When admixed with the other ingredients the flaked orpowdered parafflne, or particles of the same, will be in suspension.This mixture is applied cold to the threads 5 or to any other metallicsurfaces. Obviously, all these mixtures could be prepared equally aswell through the use of the pugmill or any other similar mechanicaldevice. My mixture can be made, and has been so made, in smallquantities in the form of a paste by the use of a mortar and pestle.Manufacturing in large quantities would be more satisfactorily carriedon with any of the known types of power operated mixers, preferably ofthe type having rotary stirring blades.

A preferred formula, which produces most excellent results, consists offour hundred parts of paraffine by volume, fifteen parts of commercialWhite lead by volume, and fifteen parts of linseed oil by volume. Theparaffine is first grated through a twenty-four mesh screen (more orless) to the form of flakes or particles or a powder. This powder, orthe flakes, is placed in a container to which is added the White lead,which is in the form of a paste which contains a certain amount oflinseed oil. The linseed oil in the proportion above specified is thenadded gradually while the mixture is being stirred and beaten up with anordinary rotary beater, or other device. This mixture is made withoutthe application of heat and is normally plastic. It remains in apastelike condition with the paraffine powder or flakes or particles insuspension, and is applied cold, and can be easily transported, and istherefore admirably adapted to the commercial market. The paste form ofthe white lead, which means that it has been previously mixed with thelinseed oil, is preferred to the form of pure white lead, which is a drypowder. In this preferred form of the compound the parafiine, as stated,is greatly in excess of the other ingredients, and is in suspension inthe form of flakes or particles or globules.

Other drying or vegetable oils of the nature of linseed oil may besubstituted for it with success. The use of white lead is not absolutelyindispensable. Sometimes it may be wholly omitted, but usually therewill be a substitution of some other similar substance having likeproperties, particularly pliability and flexibility, so that saidsubstituted material can be made to serve as a neutral filler. But theparafiine is preeminently important in my material, and is indispensablein some substantial quantity, if not in excess, and is not to besubstituted for any other substances unless they be similarly waxlikeand with substantially the same physical properties.

White lead alone, which has heretofore often been used for a purposesimilar to that of my improved thread compound, does not possess thelubricating qualities of my improved parafiine compound. Neither doother commercial compounds with which I am familiar.

Take the following practical example of a comparative use. In screwingup joints, both male and female, which are of castiron, coated with theordinary well known compounds, it is quite common to break off the maleend of the pipe because the joint is overstressed before the parts arescrewed fully home. Through the use of my improved paraffine compound ithas been found possible to screw the threaded end farther in, sometimesobtaining as much as one or two threads additional entrance beforecracking the tapped hub. Further, for instance, in making up a two inchcastiron pipe threaded joint in which one end of the pipe has a tappedhub, and the other end has a threaded spigot, when using ordinarycommercial compounds it has been found that a joint may appear to betight when being threaded up with a twenty-four inch wrench, but whichin fact is not tight. By the use of a fortyeight inch wrench handle itis usually possible to give the pipe perhaps another one-quarter oronehalf turn. handle will almost invariably break the spigot end of thepipe off near the threads. When my improved parafiine compound is used,a twentyfour inch wrench is suiiicient to keep threading the spigot endinto the tapped socket to the point 10 where the socket is split, due tothe tapered threads, and this is usually several turns more, or, inother words, several more threads engagement than is possible with whitelead alone, and

other commercial types of threading compounds 15 that are used. Ofcourse my new compound insures a tighter joint against leakage andindicates a more perfect metal to metal contact. It will be understoodthat the joints may be easily unscrewed at any time, and the metalsurface will be found clean and bright; hence joints can be taken downafter long use with great ease and without damage to the engagingsurfaces. My compound is applicable to sealed joints of all kinds in agreat variety of pipe lines carrying steam, all kinds of gases and oilsand other substances, and also in making tight joints for manhole andhandhole covers in tanks or stills or boilers operating at a hightemperature, and in a great diversity of different kinds of threaded or30 other joints used in connection with a very large number of differentkinds of machinery operating in various industrial lines.

I have heretofore stated that the use of white lead is not absolutelyindispensable, and some- 35 times it may be wholly omitted, if a propersubstitute is made for a neutral filler. In my experience I havedemonstrated this and have secured satisfactory results by the use ofsuch substitutes as powdered asbestos and also fine clay dust, providedthey are mixed with the other ingredients essential to form a successfulmixture.

What I claim is: 1. A sealing composition of the class described,

consisting of White lead, linseed oil, and parafline" particles insuspension.

2. A sealing composition of the character described, consisting of amixture of linseed oil, a plastic filler, and parafiine, the latter inexcess of the oil and filler, the mixture being normally' plastic.

3. A sealing composition of the class described, consisting ofcommercial white lead, linseed oil, these two ingredients being equal involume, and.

paraffine in a suflicient volume to form the basis' 55 6. A sealingcomposition of the class describedf consisting of white lead in acommercial pastelike form, fifteen parts, linseed oil, fifteen parts,and paraffine, four hundred parts, the mixture being normally pastelike.

FRED STEVENS.

Still further turning of the wrenchv 5

